Device for supplying fluid at tools for breaking solid material

Apparatus for breaking solid materials comprising a movable tool carrier, a cutting tool mounted on said tool carrier, said tool being moved forwardly into cutting relationship with said solid materials in response to forward movement of said carrier, means constraining said tool against rearward retraction relative to said carrier, a nozzle carried by said tool carrier and oriented to eject fluid toward a cutting zone of said cutting tool, a fluid conduit for supplying fluid to said nozzle, valve means arranged to selectively open and close said fluid line, valve control means comprising a strain gauge sensor arranged to sense compression strain of said tool during a cutting operation, and means operatively connected to said strain gauge sensor and said valve means for opening said valve means to supply fluid to said nozzle in response to said strain gauge sensor sensing a compression strain in said tool.